This invention relates to reflector devices for focusing and concentrating incident light. More specifically, this invention relates to a relatively simple and inexpensive focusing reflector for redirecting incident light for concentration at a prescribed focal zone, wherein the reflective surfaces of the reflector comprise a modified corner cube geometry.
A variety of reflector devices are available in the prior art for focusing and concentrating incident light. For example, parabolic mirrors are known for focusing light incident upon the mirror at a precise focal zone. In solar energy applications, a parabolic mirror is advantageously used to reflect the sun's rays for concentration upon heat pipes, photocells, and the like at the focal zone for converting the concentrated solar energy to a more useful form. However, parabolic mirrors are relatively difficult and expensive to design and construct in that each mirror must be formed according to a precise parabolic geometry for satisfactory reflection and focusing of the incident light. Moreover, the parabolic mirror must be supported by a rigid structural framework for maintaining the parabolic geometry of the mirror, and this entire framework must be precisely oriented with respect to the light source for satisfactory concentration of the light energy. In solar applications, this results in a relatively complex and expensive system which must be accurately and gradually shifted in position according to the season and time of day.
The prior art further includes a large number of relatively simple and inexpensive reflector devices, such as plain mirrors and the like, which are capable of reflecting incident light with high efficiency. However, these traditional reflector devices are not useful in solar energy applications in that they typically reflect the incident light without concentration at an angle complementary to the angle of incidence. Other reflector devices such as conventional corner cube reflectors have been provided with an array of corners cubes each having three mutually perpendicular facets for redirecting incident light back toward the light source throughout a range of angles of incidence. While these corner cube devices have broad applicability in the automobile and bicycle safety reflector lens field, they too are not useful in solar energy applications because of their failure to concentrate the redirected light at a predetermined focal zone.
It is desirable, therefore, to provide a reflector device for reflecting and concentrating incident light energy wherein that reflector device is relatively inexpensive in design and manufacture, and does not require precision tracking of the light source for efficient operation. The present invention provides such an improved and inexpensive focusing reflector device.